The Targa roofs in currently produced cars have to be completely detached from the car body and manually carried to a storage space in the cockpit, in the trunk or left in a garage or at home. The conversion of a current rigid Targa roof from a closed condition to an open condition involves a person unlocking the roof from the inside the car and then going outside the vehicle to lift the somewhat heavy weight roof for separate storage. If to be stored in the vehicle, the result is the loss of otherwise useful storage space behind the front seat or in the trunk. This is particularly critical since storage space in typical sports cars which employ the Targa roof is initially limited.
There are a number of prior patents which seek to allow the roof to be moved from its normal position to a storage position without the disengagement from the vehicle.
U.S. Pat. No. 4,165,122 of Bertone describes a roof panel Which is pivoted upright by a system of levers and then lowered into its storage space behind the seat back and which is operable from within the vehicle. U.S. Pat. No. 4,895,409 of Konishe et al shows a roof rear panel structure which is similarly retracted rearwardly and downwardly into a storing space behind the vehicle rear seat. Guide rails, sliding plates and sliding shoes are employed. There are disadvantages to these schemes. The linkage mechanisms are complex and a large uninterrupted free space has to be left clear behind the car seats to store the roof. The retraction cannot be done at normal car speeds due to the roof's intermediate vertical position above the car body which captures the wind stream and would tend to lift and bend the retracting roof.
U.S. Pat. No. 1,722,227 of Lukesh describe a roof which slides backwards together with the whole integral rear part of the upper body including the rear window and rear side walls. After retraction, the roof and rear part of the upper body are stored above and behind the rear of the car disabling the use of a rear seat 15.
U.S. Pat. No. 4,168,859 of Breitschwerdt et al shows a similar displacement of the entire rear vehicle upper part including the rear window and sidewalls, the former being additionally lowerable into a trunk space. The disadvantage of these schemes is the fact that almost the whole upper body has to retract with the roof, affecting the structural integrity of the car body and its weather sealing properties. A strong and precise retraction mechanism has to be used, as well as complicated weather sealing.
U.S. Pat. No. 4,801,174 of Hirshberg et al describes a transparent roof panel of less than full width which slides rearward in a downward arch and is stored in proximate parallelism to the rear window, resulting in a double-pane rear window. The disadvantage of this scheme are that the construction is limited to the use of a moving glass panel since otherwise the driver's rear view would be obstructed and necessitates a curved panel which limits the design choices for a vehicle designer. Further, provision must be made to continue the ability of the rear window to be raised and lowered to provide rear access into the passenger compartment.